One of the most potent contaminants of the redshifted 21-cm signal from the CD/EoR is the astrophysical foregrounds. They constitute all the emissions in the radio sky brighter than the target signal present at the observing frequency. They include diffuse galactic synchrotron emission (DGSE), galactic and extragalactic free-free emission, and emission from astrophysical sources, viz. star-forming galaxies (SFGs) and active galactic nuclei (AGNs). These emission sources themselves are of significant scientific interest (for example [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}) and are currently being studied actively with state of the art radio telescopes. However, for 21-cm cosmology, these contaminants need to be removed from the relevant data sets. DGSE is the dominant emission at frequencies \(\sim \)  150 MHz at angular scales \(\gtrsim \) degree, while the extragalactic sources dominate at smaller angular scales. Since radio emissions arise from synchrotron processes, it is expected that these sources are spectrally smooth, i.e., do not have frequency structures contrary to the Hi signal [14]}.
